class ArtGallery(object):
""" This class resolves The art gallery problem.
It is a visibility problem in computational geometry.
Guarding an art gallery with the minimum number of guards who together
can observe the whole gallery
"""
def __init__(self, point):
self._point = Point(point.id, point.x, point.y)
self._points = [point]
self._polygon = [(point.x, point.y)]
self._triangulation = Triangulation(self._points)
self._color = Coloring(self._points, self._triangulation)
self.lock = threading.RLock()
self.version = 0
@staticmethod
def load(file_name):
points = []
with open(file_name, "r") as hfile:
hfile.readline()
i = 0
for line in hfile:
x, y = line.split()
point = Point(i, Decimal(x), Decimal(y))
i += 1
points.append(point)
return points
def _update(self):
self._points.sort()
self._polygon = []
for p in self._points:
self._polygon.append((p.x, p.y))
def get_polygon(self):
with self.lock:
return self._polygon
def get_process_point(self):
with self.lock:
return self._point
def get_points(self):
with self.lock:
return self._points
def get_diagonals(self):
with self.lock:
return self._triangulation.get_diagonals()
def get_min_color(self):
with self.lock:
return self._color.get_min_color()
def is_guard(self, point):
with self.lock:
return point.color == self._color.get_min_color()
def include(self, point):
""" Add a new point to the art gallery """
with self.lock:
self._points.append(Point(point.id, point.x, point.y))
self._update()
triangulated = self._triangulation.process()
if (triangulated):
self._color.process()
self.version += 1
